Re: [PATCH v4 6/7] Bluetooth: mediatek: Add protocol support for MediaTek serial devices

From: Andy Shevchenko
Date: Wed Jun 27 2018 - 13:00:02 EST

On Wed, Jun 27, 2018 at 8:43 AM, <sean.wang@xxxxxxxxxxxx> wrote:
> From: Sean Wang <sean.wang@xxxxxxxxxxxx>
>

> +config BT_HCIBTUART_MTK
> + tristate "MediaTek HCI UART driver"
> + depends on BT_HCIBTUART

> + default y

Perhaps it's an overkill for users which would like to have less
amount on stuff in kernel.


> +#include <asm/unaligned.h>
> +#include <linux/atomic.h>
> +#include <linux/clk.h>
> +#include <linux/firmware.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/serdev.h>

> +#include <net/bluetooth/bluetooth.h>
> +#include <net/bluetooth/hci_core.h>
> +
> +#include "h4_recv.h"
> +#include "btuart.h"
> +#include "btmtkuart.h"
> +
> +static void mtk_stp_reset(struct mtk_stp_splitter *sp)
> +{
> + sp->cursor = 2;
> + sp->dlen = 0;
> +}
> +
> +static const unsigned char *
> +mtk_stp_split(struct btuart_dev *bdev, struct mtk_stp_splitter *sp,
> + const unsigned char *data, int count, int *sz_h4)
> +{
> + struct mtk_stp_hdr *shdr;
> +
> + /* The cursor is reset when all the data of STP is consumed out. */
> + if (!sp->dlen && sp->cursor >= 6)
> + sp->cursor = 0;
> +
> + /* Filling pad until all STP info is obtained. */
> + while (sp->cursor < 6 && count > 0) {
> + sp->pad[sp->cursor] = *data;
> + sp->cursor++;
> + data++;
> + count--;
> + }
> +
> + /* Retrieve STP info and have a sanity check. */
> + if (!sp->dlen && sp->cursor >= 6) {
> + shdr = (struct mtk_stp_hdr *)&sp->pad[2];
> + sp->dlen = shdr->dlen1 << 8 | shdr->dlen2;
> +
> + /* Resync STP when unexpected data is being read. */
> + if (shdr->prefix != 0x80 || sp->dlen > 2048) {
> + bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
> + shdr->prefix, sp->dlen);
> + mtk_stp_reset(sp);
> + }
> + }
> +
> + /* Directly quit when there's no data found for H4 can process. */
> + if (count <= 0)
> + return NULL;
> +
> + /* Tranlate to how much the size of data H4 can handle so far. */
> + *sz_h4 = min_t(int, count, sp->dlen);
> + /* Update the remaining size of STP packet. */
> + sp->dlen -= *sz_h4;
> +
> + /* Data points to STP payload which can be handled by H4. */
> + return data;
> +}
> +
> +static int mtk_stp_send(struct btuart_dev *bdev, struct sk_buff *skb)
> +{
> + struct mtk_stp_hdr *shdr;
> + struct sk_buff *new_skb;
> + int dlen;
> +
> + memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
> + dlen = skb->len;
> +
> + /* Make sure of STP header at least has 4-bytes free space to fill. */
> + if (unlikely(skb_headroom(skb) < MTK_STP_HDR_SIZE)) {
> + new_skb = skb_realloc_headroom(skb, MTK_STP_HDR_SIZE);
> + kfree_skb(skb);
> + skb = new_skb;
> + }
> +
> + /* Build for STP packet format. */
> + shdr = skb_push(skb, MTK_STP_HDR_SIZE);
> + mtk_make_stp_hdr(shdr, 0, dlen);
> + skb_put_zero(skb, MTK_STP_TLR_SIZE);
> +
> + skb_queue_tail(&bdev->txq, skb);
> +
> + return 0;
> +}
> +
> +static int mtk_hci_wmt_sync(struct btuart_dev *bdev, u8 opcode, u8 flag,
> + u16 plen, const void *param)
> +{
> + struct mtk_hci_wmt_cmd wc;
> + struct mtk_wmt_hdr *hdr;
> + struct sk_buff *skb;
> + u32 hlen;
> +
> + hlen = sizeof(*hdr) + plen;
> + if (hlen > 255)
> + return -EINVAL;
> +
> + hdr = (struct mtk_wmt_hdr *)&wc;
> + mtk_make_wmt_hdr(hdr, opcode, plen, flag);
> + memcpy(wc.data, param, plen);
> +
> + atomic_inc(&bdev->hdev->cmd_cnt);
> +
> + skb = __hci_cmd_sync_ev(bdev->hdev, 0xfc6f, hlen, &wc, HCI_VENDOR_PKT,
> + HCI_INIT_TIMEOUT);
> +
> + if (IS_ERR(skb)) {
> + int err = PTR_ERR(skb);
> +
> + bt_dev_err(bdev->hdev, "Failed to send wmt cmd (%d)\n", err);
> + return err;
> + }
> +
> + kfree_skb(skb);
> +
> + return 0;
> +}
> +
> +static int mtk_setup_fw(struct btuart_dev *bdev)
> +{
> + const struct firmware *fw;
> + struct device *dev;
> + const char *fwname;
> + const u8 *fw_ptr;
> + size_t fw_size;
> + int err, dlen;
> + u8 flag;
> +
> + dev = &bdev->serdev->dev;
> + fwname = FIRMWARE_MT7622;
> +
> + err = request_firmware(&fw, fwname, dev);
> + if (err < 0) {
> + bt_dev_err(bdev->hdev, "Failed to load firmware file (%d)",
> + err);
> + return err;
> + }
> +
> + fw_ptr = fw->data;
> + fw_size = fw->size;
> +
> + /* The size of patch header is 30 bytes, should be skip. */
> + if (fw_size < 30)
> + return -EINVAL;
> +
> + fw_size -= 30;
> + fw_ptr += 30;
> +
> + while (fw_size > 0) {
> + dlen = min_t(int, 250, fw_size);
> +
> + /* Tell deivice the position in sequence. */
> + flag = (fw_size - dlen <= 0) ? 3 :
> + (fw_size < fw->size - 30) ? 2 : 1;
> +
> + err = mtk_hci_wmt_sync(bdev, MTK_WMT_PATCH_DWNLD, flag, dlen,
> + fw_ptr);
> + if (err < 0)
> + break;
> +
> + fw_size -= dlen;
> + fw_ptr += dlen;
> + }
> +
> + release_firmware(fw);
> +
> + return err;
> +}
> +
> +void *mtk_btuart_init(struct device *dev)
> +{
> + struct mtk_bt_dev *soc;
> +
> + soc = devm_kzalloc(dev, sizeof(*soc), GFP_KERNEL);
> + if (!soc)
> + return ERR_PTR(-ENOMEM);
> +
> + soc->sp = devm_kzalloc(dev, sizeof(*soc->sp), GFP_KERNEL);
> + if (!soc->sp)
> + return ERR_PTR(-ENOMEM);
> +
> + soc->clk = devm_clk_get(dev, "ref");
> + if (IS_ERR(soc->clk))
> + return ERR_CAST(soc->clk);
> +
> + return soc;
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_init);
> +
> +int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> +
> + return mtk_stp_send(bdev, skb);
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_send);
> +
> +int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct hci_event_hdr *hdr = (void *)skb->data;
> +
> + /* Fix up the vendor event id with HCI_VENDOR_PKT instead of
> + * 0xe4 so that btmon can parse the kind of vendor event properly.
> + */
> + if (hdr->evt == 0xe4)
> + hdr->evt = HCI_VENDOR_PKT;
> +
> + /* Each HCI event would go through the core. */
> + return hci_recv_frame(hdev, skb);
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_hci_frame);
> +
> +int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
> +{
> + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> + const unsigned char *p_left = data, *p_h4;
> + const struct btuart_vnd *vnd = bdev->vnd;
> + struct mtk_bt_dev *soc = bdev->data;
> + int sz_left = count, sz_h4, adv;
> + struct device *dev;
> + int err;
> +
> + dev = &bdev->serdev->dev;
> +
> + while (sz_left > 0) {
> + /* The serial data received from MT7622 BT controller is
> + * at all time padded around with the STP header and tailer.
> + *
> + * A full STP packet is looking like
> + * -----------------------------------
> + * | STP header | H:4 | STP tailer |
> + * -----------------------------------
> + * but it don't guarantee to contain a full H:4 packet which
> + * means that it's possible for multiple STP packets forms a
> + * full H:4 packet and whose length recorded in STP header can
> + * shows up the most length the H:4 engine can handle in one
> + * time.
> + */
> +
> + p_h4 = mtk_stp_split(bdev, soc->sp, p_left, sz_left, &sz_h4);
> + if (!p_h4)
> + break;
> +
> + adv = p_h4 - p_left;
> + sz_left -= adv;
> + p_left += adv;
> +
> + bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
> + sz_h4, vnd->recv_pkts,
> + vnd->recv_pkts_cnt);
> + if (IS_ERR(bdev->rx_skb)) {
> + err = PTR_ERR(bdev->rx_skb);
> + bt_dev_err(bdev->hdev,
> + "Frame reassembly failed (%d)", err);
> + bdev->rx_skb = NULL;
> + return err;
> + }
> +
> + sz_left -= sz_h4;
> + p_left += sz_h4;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_recv);
> +
> +int mtk_btuart_setup(struct hci_dev *hdev)
> +{
> + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> + struct mtk_bt_dev *soc = bdev->data;
> + struct device *dev;
> + u8 param = 0x1;
> + int err = 0;
> +
> + dev = &bdev->serdev->dev;
> +
> + mtk_stp_reset(soc->sp);
> +
> + /* Enable the power domain and clock the device requires. */
> + pm_runtime_enable(dev);
> + err = pm_runtime_get_sync(dev);
> + if (err < 0)
> + goto err_pm2;
> +
> + err = clk_prepare_enable(soc->clk);
> + if (err < 0)
> + goto err_pm1;
> +
> + /* Setup a firmware which the device definitely requires. */
> + err = mtk_setup_fw(bdev);
> + if (err < 0)
> + goto err_clk;
> +
> + /* Activate funciton the firmware providing to. */
> + err = mtk_hci_wmt_sync(bdev, MTK_WMT_RST, 0x4, 0, 0);
> + if (err < 0)
> + goto err_clk;
> +
> + /* Enable Bluetooth protocol. */
> + err = mtk_hci_wmt_sync(bdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
> + &param);
> + if (err < 0)
> + goto err_clk;
> +
> + set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
> +
> + return 0;
> +err_clk:
> + clk_disable_unprepare(soc->clk);
> +err_pm1:
> + pm_runtime_put_sync(dev);
> +err_pm2:
> + pm_runtime_disable(dev);
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_setup);
> +
> +int mtk_btuart_shutdown(struct hci_dev *hdev)
> +{
> + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> + struct device *dev = &bdev->serdev->dev;
> + struct mtk_bt_dev *soc = bdev->data;
> + u8 param = 0x0;
> +
> + /* Disable the device. */
> + mtk_hci_wmt_sync(bdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param), &param);
> +
> + /* Shutdown the clock and power domain the device requires. */
> + clk_disable_unprepare(soc->clk);
> + pm_runtime_put_sync(dev);
> + pm_runtime_disable(dev);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(mtk_btuart_shutdown);
> +
> +MODULE_AUTHOR("Sean Wang <sean.wang@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Bluetooth Support for MediaTek Serial Devices");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/bluetooth/btmtkuart.h b/drivers/bluetooth/btmtkuart.h
> new file mode 100644
> index 0000000..e76ab23e
> --- /dev/null
> +++ b/drivers/bluetooth/btmtkuart.h
> @@ -0,0 +1,119 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2018 MediaTek Inc.
> + *
> + * Bluetooth support for MediaTek serial devices
> + *
> + * Author: Sean Wang <sean.wang@xxxxxxxxxxxx>
> + *
> + */
> +
> +#define FIRMWARE_MT7622 "mediatek/mt7622pr2h.bin"
> +
> +#define MTK_STP_HDR_SIZE 4
> +#define MTK_STP_TLR_SIZE 2
> +#define MTK_WMT_HDR_SIZE 5
> +#define MTK_WMT_CMD_SIZE (MTK_WMT_HDR_SIZE + MTK_STP_HDR_SIZE + \
> + MTK_STP_TLR_SIZE + HCI_ACL_HDR_SIZE)
> +
> +enum {
> + MTK_WMT_PATCH_DWNLD = 0x1,
> + MTK_WMT_FUNC_CTRL = 0x6,
> + MTK_WMT_RST = 0x7
> +};
> +
> +struct mtk_stp_hdr {
> + __u8 prefix;
> + __u8 dlen1:4;
> + __u8 type:4;
> + __u8 dlen2:8;
> + __u8 cs;
> +} __packed;
> +
> +struct mtk_wmt_hdr {
> + __u8 dir;
> + __u8 op;
> + __le16 dlen;
> + __u8 flag;
> +} __packed;
> +
> +struct mtk_hci_wmt_cmd {
> + struct mtk_wmt_hdr hdr;
> + __u8 data[256];
> +} __packed;
> +
> +struct mtk_stp_splitter {
> + u8 pad[6];
> + u8 cursor;
> + u16 dlen;
> +};
> +
> +struct mtk_bt_dev {
> + struct clk *clk;
> + struct completion wmt_cmd;
> + struct mtk_stp_splitter *sp;
> +};
> +
> +static inline void mtk_make_stp_hdr(struct mtk_stp_hdr *hdr, u8 type, u32 dlen)
> +{
> + __u8 *p = (__u8 *)hdr;
> +
> + hdr->prefix = 0x80;
> + hdr->dlen1 = (dlen & 0xf00) >> 8;
> + hdr->type = type;
> + hdr->dlen2 = dlen & 0xff;
> + hdr->cs = p[0] + p[1] + p[2];
> +}
> +
> +static inline void mtk_make_wmt_hdr(struct mtk_wmt_hdr *hdr, u8 op, u16 plen,
> + u8 flag)
> +{
> + hdr->dir = 1;
> + hdr->op = op;
> + hdr->dlen = cpu_to_le16(plen + 1);
> + hdr->flag = flag;
> +}
> +
> +#if IS_ENABLED(CONFIG_BT_HCIBTUART_MTK)
> +
> +void *mtk_btuart_init(struct device *dev);
> +int mtk_btuart_setup(struct hci_dev *hdev);
> +int mtk_btuart_shutdown(struct hci_dev *hdev);
> +int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb);
> +int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb);
> +int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data, size_t count);
> +
> +#else
> +
> +static void *mtk_btuart_init(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static inline int mtk_btuart_setup(struct hci_dev *hdev)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int mtk_btuart_shutdown(struct hci_dev *hdev)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data,
> + size_t count)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +#endif
> diff --git a/drivers/bluetooth/btuart.c b/drivers/bluetooth/btuart.c
> index ab7f836..169bf1a 100644
> --- a/drivers/bluetooth/btuart.c
> +++ b/drivers/bluetooth/btuart.c
> @@ -35,6 +35,7 @@
> #include "h4_recv.h"
> #include "btuart.h"
> #include "btbcm.h"
> +#include "btmtkuart.h"
>
> #define VERSION "1.0"
>
> @@ -396,6 +397,12 @@ static const struct h4_recv_pkt bcm_recv_pkts[] = {
> { BCM_RECV_NULL, .recv = hci_recv_diag },
> };
>
> +static const struct h4_recv_pkt mtk_recv_pkts[] = {
> + { H4_RECV_ACL, .recv = hci_recv_frame },
> + { H4_RECV_SCO, .recv = hci_recv_frame },
> + { H4_RECV_EVENT, .recv = mtk_btuart_hci_frame },
> +};
> +
> static const struct btuart_vnd bcm_vnd = {
> .recv_pkts = bcm_recv_pkts,
> .recv_pkts_cnt = ARRAY_SIZE(bcm_recv_pkts),
> @@ -403,6 +410,16 @@ static const struct btuart_vnd bcm_vnd = {
> .setup = bcm_setup,
> };
>
> +static const struct btuart_vnd mtk_vnd = {
> + .recv_pkts = mtk_recv_pkts,
> + .recv_pkts_cnt = ARRAY_SIZE(mtk_recv_pkts),
> + .init = mtk_btuart_init,
> + .setup = mtk_btuart_setup,
> + .shutdown = mtk_btuart_shutdown,
> + .send = mtk_btuart_send,
> + .recv = mtk_btuart_recv,
> +};
> +
> static const struct h4_recv_pkt default_recv_pkts[] = {
> { H4_RECV_ACL, .recv = hci_recv_frame },
> { H4_RECV_SCO, .recv = hci_recv_frame },
> @@ -487,6 +504,7 @@ static void btuart_remove(struct serdev_device *serdev)
> #ifdef CONFIG_OF
> static const struct of_device_id btuart_of_match_table[] = {
> { .compatible = "brcm,bcm43438-bt", .data = &bcm_vnd },
> + { .compatible = "mediatek,mt7622-bluetooth", .data = &mtk_vnd },
> { }
> };
> MODULE_DEVICE_TABLE(of, btuart_of_match_table);
> --
> 2.7.4
>



--
With Best Regards,
Andy Shevchenko